Ever wonder how Intel's retail heatsinks stack up against the best aftermarket CPU coolers
out there?

Does Intel make a better heatsink for its processors
than companies like Thermalright, Zalman, Scythe or Coolermaster produce
for enthusiasts? That's a good question, so let's spend
some quality time with Intel's newest 45nm Core 2 Extreme
class reference cooler and find out. Meet the aptly name Intel FCLGA4-S socket
775 reference heatsink.

Judging
by Frostytech's Top 5
Heatsinks chart, the popularity of tower heatsinks with exposed heatpipe bases has made
competition between CPU coolers pretty cut throat this year. Almost every week for the past while
Frostytech seen a new heatsink that blows away what was considered 'performance' just a short
time before. Reference heatsinks on the other hand tend to
change a lot less frequently, which has led many consumers to develop an 'I'd never use it" stigma around the boxed thermal solutions provided by
the processor manufacturer.

In this review Frostytech will be comparing
the Intel FCLGA4-S reference heatsink, which is boxed with retail 45nm
Intel Core 2 Extreme QX6850 processors (and others), against one
hundred Intel socket 775 heatsinks from every imaginable manufacturer. As
always, tests will be conducted on the Frostytech Mk.II
synthetic thermal test platform at 150W and 85W
heat loads. The FCLGA4-S reference heatsink was provided by Intel in an unboxed
state, the only thing it came with was a pre-applied patch of thermal compound,
and this was removed prior to testing.

Unlike most AMD/Intel supplied thermal solutions, the Intel FCLGA4-S reference
heatsink features a touch of style in the form
of a blue-LED illuminated translucent 110mm diameter fan. The illumination looks nice, the underlying fan frame resembles a radiation warning sign in a frosty
blue glow.

The Pulse Width Modulation (PWM) fan has been customized slightly, Delta have
added a small mechanical switch the user can flick to set the fan into fixed
"performance" or "quiet" modes. At full speed the Delta
fan spins at 2900RPM, when set to quiet mode it drops to ~2000RPM. The full range in a PWM autonomous setting is approximately
1000-to-2900RPM. A single 4-pin cable supplies power to the
heatsink.

The other notable innovation with Intel's FCLGA4-S reference heatsink is harder to see,
a vapour chamber. At 413grams, the vapour chamber also makes the
Intel FCLGA4-S heatsink suprisingly lightweight for its 134mm wingspan. Intel engineers
apparently built the heatsink with a sub-550gram weight target in mind, and
the stocky heatpipe was seen as a better option than a heavy solid
copper core.

The 41mm diameter copper "thermal chamber" works along a
similar principle as a heatpipe, using a working fluid under a vacuum. The
low pressure causes the fluid to change states when heat is applied, allowing
the vapour to rapidly conduct heat between hot and cold surfaces. A solid
metal block by comparison would rely upon the metals conductive
properties to move heat from the base and distribute it along the cylindrical
walls to which the fins are soldered.

The Intel FCLGA4-S reference heatsink by comparison
has relatively thin copper walls around the hollow chamber, as you can
see in this cutaway image below. The walls are no more than 0.5-1mm thick,
and a sintered metal wick is evidently used to return condensed working fluid
back to the hot side. The copper base is surprisingly thin too, about 4mm. The
net result is a really lightweight heatsink for its thermal performance
capabilities.

Around the copper chamber are soldered about 200
thin nickel plated stacked aluminum fins. A small fold at the base creates a tab about
a millimeter wide to solder to the copper. As you can see below, the
copper-to-fin interface is close, but there are small voids here and
there. Comparatively, the components of the copper chamber are brazed together at a
higher temperature to ensure the joints never compromise the vacuum inside.

FrostyTech's Test Methodologies are outlined in detail here if you care to know what equipment is
used, and the parameters under which the tests are conducted. Now let's move
forward and take a closer look at this heatsink, its acoustic characteristics,
and of course its performance in the thermal tests!